feat: refresh PocketBase auth tokens automatically (#4)

Co-authored-by: Joshua Higgins <joshuafhiggins@gmail.com>

src/context/AuthContext.tsx

@@ -1,6 +1,8 @@
-import React, { createContext, useContext, useState, useEffect, useCallback } from 'react';
+import React, { createContext, useContext, useState, useEffect, useCallback, useRef } from 'react';
+import { AppState } from 'react-native';
 import AsyncStorage from '@react-native-async-storage/async-storage';
-import api from '../services/api';
+import api, { isAuthCollection, isRevokedAuthError } from '../services/api';
+import { getJwtExpiryMs } from '../services/jwtExpiry';
 import { syncDevicesToWidget } from '../services/widgetSync';
 import { AuthResponse, User } from '../types';
 
@@ -17,6 +19,22 @@ interface AuthContextType {
 
 const AuthContext = createContext<AuthContextType | undefined>(undefined);
 
+const AUTH_COLLECTION_KEY = 'auth_collection';
+const REFRESH_BEFORE_EXPIRY_MS = 60_000;
+const MAX_REFRESH_DELAY_MS = 2_147_483_647;
+const REFRESH_RETRY_MS = 30_000;
+const REFRESH_BACKOFF_MS = 15_000;
+
+function msUntilRefresh(token: string): number | null {
+  const expiresAt = getJwtExpiryMs(token);
+  if (expiresAt == null) return null;
+  return expiresAt - Date.now() - REFRESH_BEFORE_EXPIRY_MS;
+}
+
+function collectionFromUser(user: User | null): 'users' | '_superusers' | null {
+  return isAuthCollection(user?.collectionName) ? user.collectionName : null;
+}
+
 export const AuthProvider: React.FC<{ children: React.ReactNode }> = ({ children }) => {
   const [user, setUser] = useState<User | null>(null);
   const [serverAddress, setServerAddress] = useState<string | null>(null);
@@ -24,44 +42,192 @@ export const AuthProvider: React.FC<{ children: React.ReactNode }> = ({ children
   const [isLoading, setIsLoading] = useState(true);
   const [canCreate, setCanCreate] = useState<boolean | null>(null);
 
-  const clearSession = useCallback(async () => {
+  const refreshTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
-    await AsyncStorage.multiRemove(['auth_token', 'auth_user', 'auth_can_create']);
+  const refreshingRef = useRef(false);
+  const sessionWriteRef = useRef<Promise<void>>(Promise.resolve());
+  const refreshSessionRef = useRef<() => Promise<void>>(async () => {});
+  const armRefreshTimerRef = useRef<(token: string, overdueDelay?: number) => void>(() => {});
 
+  const enqueueSessionWrite = useCallback((task: () => Promise<void>) => {
+    const run = sessionWriteRef.current.then(task, task);
+    sessionWriteRef.current = run.then(
+      () => undefined,
+      () => undefined,
+    );
+    return run;
+  }, []);
+
+  const clearRefreshTimer = useCallback(() => {
+    if (refreshTimerRef.current != null) {
+      clearTimeout(refreshTimerRef.current);
+      refreshTimerRef.current = null;
+    }
+  }, []);
+
+  const clearSession = useCallback(async () => {
+    clearRefreshTimer();
     api.clearToken();
     api.clearCanCreate();
+    api.clearAuthCollection();
     setToken(null);
     setUser(null);
     setCanCreate(null);
+
+    await enqueueSessionWrite(async () => {
+      await AsyncStorage.multiRemove([
+        'auth_token',
+        'auth_user',
+        'auth_can_create',
+        AUTH_COLLECTION_KEY,
+      ]);
+    });
+  }, [clearRefreshTimer, enqueueSessionWrite]);
+
+  const armRefreshTimer = useCallback((nextToken: string, overdueDelay = 0) => {
+    clearRefreshTimer();
+    const untilRefresh = msUntilRefresh(nextToken);
+    if (untilRefresh == null) return;
+
+    const delay = untilRefresh <= 0 ? overdueDelay : Math.min(untilRefresh, MAX_REFRESH_DELAY_MS);
+    const rescheduleOnly = untilRefresh > MAX_REFRESH_DELAY_MS;
+
+    refreshTimerRef.current = setTimeout(() => {
+      refreshTimerRef.current = null;
+      const latest = api.getToken();
+      if (!latest) return;
+      if (rescheduleOnly) {
+        armRefreshTimerRef.current(latest);
+        return;
+      }
+      void refreshSessionRef.current();
+    }, delay);
+  }, [clearRefreshTimer]);
+
+  const refreshSession = useCallback(async () => {
+    if (refreshingRef.current || !api.getToken()) return;
+
+    refreshingRef.current = true;
+    try {
+      await api.refreshAuth();
+    } catch {
+      // The failure listener either keeps the session and retries, or signs out.
+    } finally {
+      refreshingRef.current = false;
+    }
+  }, []);
+
+  const handleRefreshFailure = useCallback(async (error: unknown) => {
+    if (isRevokedAuthError(error)) {
+      await clearSession();
+      return;
+    }
+
+    if (!api.getToken()) return;
+
+    clearRefreshTimer();
+    refreshTimerRef.current = setTimeout(() => {
+      refreshTimerRef.current = null;
+      void refreshSessionRef.current();
+    }, REFRESH_RETRY_MS);
+  }, [clearRefreshTimer, clearSession]);
+
+  const persistRefreshedAuth = useCallback(async (auth: AuthResponse) => {
+    await enqueueSessionWrite(async () => {
+      if (api.getToken() !== auth.token) return;
+
+      const collection = api.getAuthCollection();
+      const pairs: [string, string][] = [
+        ['auth_token', auth.token],
+        ['auth_user', JSON.stringify(auth.record)],
+      ];
+      if (collection) {
+        pairs.push([AUTH_COLLECTION_KEY, collection]);
+      }
+      if (collection === '_superusers') {
+        pairs.push(['auth_can_create', 'true']);
+      }
+
+      await AsyncStorage.multiSet(pairs);
+      if (api.getToken() !== auth.token) return;
+
+      setToken(auth.token);
+      setUser(auth.record);
+      if (collection === '_superusers') {
+        setCanCreate(true);
+      }
+      armRefreshTimerRef.current(auth.token, REFRESH_BACKOFF_MS);
+    });
+  }, [enqueueSessionWrite]);
+
+  const watchToken = useCallback((nextToken: string) => {
+    const untilRefresh = msUntilRefresh(nextToken);
+    if (untilRefresh != null && untilRefresh <= 0) {
+      void refreshSessionRef.current();
+      return;
+    }
+    armRefreshTimerRef.current(nextToken);
   }, []);
 
+  useEffect(() => {
+    refreshSessionRef.current = refreshSession;
+    armRefreshTimerRef.current = armRefreshTimer;
+  }, [armRefreshTimer, refreshSession]);
+
   useEffect(() => {
     api.setUnauthorizedHandler(clearSession);
+    api.setAuthUpdateListener(persistRefreshedAuth);
+    api.setAuthFailureListener(handleRefreshFailure);
 
     return () => {
       api.setUnauthorizedHandler(null);
+      api.setAuthUpdateListener(null);
+      api.setAuthFailureListener(null);
+      clearRefreshTimer();
     };
-  }, [clearSession]);
+  }, [clearRefreshTimer, clearSession, handleRefreshFailure, persistRefreshedAuth]);
 
   useEffect(() => {
     let cancelled = false;
 
-    void AsyncStorage.multiGet([
+    void (async () => {
-      'auth_token',
+      try {
-      'auth_user',
+        const [
-      'auth_server_address',
+          [, storedToken],
-      'auth_can_create',
+          [, storedUser],
-    ]).then(
+          [, storedServerAddress],
-      ([[, storedToken], [, storedUser], [, storedServerAddress], [, storedCanCreate]]) => {
+          [, storedCanCreate],
+          [, storedCollection],
+        ] = await AsyncStorage.multiGet([
+          'auth_token',
+          'auth_user',
+          'auth_server_address',
+          'auth_can_create',
+          AUTH_COLLECTION_KEY,
+        ]);
         if (cancelled) return;
 
-        if (storedCanCreate) {
+        let restoredUser: User | null = null;
-          setCanCreate(storedCanCreate === 'true');
+        if (storedToken && storedUser) {
+          restoredUser = JSON.parse(storedUser) as User;
+          api.setToken(storedToken);
+          setToken(storedToken);
+          setUser(restoredUser);
         }
 
-        if (storedToken && storedUser) {
+        const collection = isAuthCollection(storedCollection)
-          setToken(storedToken);
+          ? storedCollection
-          api.setToken(storedToken);
+          : collectionFromUser(restoredUser);
-          setUser(JSON.parse(storedUser));
+        if (collection) {
+          api.setAuthCollection(collection);
+        }
+
+        if (collection === '_superusers') {
+          api.setCanCreate(true);
+          setCanCreate(true);
+        } else if (storedCanCreate) {
+          const restoredCanCreate = storedCanCreate === 'true';
+          api.setCanCreate(restoredCanCreate);
+          setCanCreate(restoredCanCreate);
         }
 
         if (storedServerAddress) {
@@ -69,36 +235,78 @@ export const AuthProvider: React.FC<{ children: React.ReactNode }> = ({ children
           api.setAddress(storedServerAddress + '/api');
         }
 
-        setIsLoading(false);
+        const untilRefresh = storedToken ? msUntilRefresh(storedToken) : null;
-      },
+        const refreshIsDue = !!storedToken && !!restoredUser && untilRefresh != null && untilRefresh <= 0;
-      error => {
+
+        if (refreshIsDue) {
+          try {
+            // Hold the loading gate so an expired token does not flash the device list.
+            await api.refreshAuth();
+          } catch {
+            // Revoked tokens sign out; transient failures keep the session and retry.
+          }
+        } else if (storedToken && restoredUser) {
+          watchToken(storedToken);
+        }
+
+        if (!cancelled) {
+          setIsLoading(false);
+        }
+      } catch (error) {
         if (cancelled) return;
         console.error('Failed to load auth', error);
         setIsLoading(false);
       }
-    );
+    })();
 
     return () => {
       cancelled = true;
     };
+  }, [watchToken]);
+
+  useEffect(() => {
+    const subscription = AppState.addEventListener('change', nextState => {
+      if (nextState !== 'active') return;
+
+      const currentToken = api.getToken();
+      if (!currentToken) return;
+
+      const untilRefresh = msUntilRefresh(currentToken);
+      if (untilRefresh == null) return;
+      if (untilRefresh <= 0) {
+        void refreshSessionRef.current();
+        return;
+      }
+      armRefreshTimerRef.current(currentToken);
+    });
+
+    return () => {
+      subscription.remove();
+    };
   }, []);
 
-  const login = async (serverAddress: string, identity: string, password: string) => {
+  const login = async (nextServerAddress: string, identity: string, password: string) => {
-    try {
+    const response: AuthResponse = await api.authenticate(nextServerAddress, identity, password);
-      const response: AuthResponse = await api.authenticate(serverAddress, identity, password);
+    const collection = api.getAuthCollection();
-      
+
-      await AsyncStorage.setItem('auth_token', response.token);
+    await enqueueSessionWrite(async () => {
-      await AsyncStorage.setItem('auth_user', JSON.stringify(response.record));
+      const pairs: [string, string][] = [
-      await AsyncStorage.setItem('auth_server_address', serverAddress);
+        ['auth_token', response.token],
-      await AsyncStorage.setItem('auth_can_create', api.getCanCreate() ? 'true' : 'false');
+        ['auth_user', JSON.stringify(response.record)],
-      
+        ['auth_server_address', nextServerAddress],
-      setToken(response.token);
+        ['auth_can_create', api.getCanCreate() ? 'true' : 'false'],
-      setUser(response.record);
+      ];
-      setServerAddress(serverAddress);
+      if (collection) {
-      setCanCreate(api.getCanCreate() || false);
+        pairs.push([AUTH_COLLECTION_KEY, collection]);
-    } catch (error) {
+      }
-      throw error;
+      await AsyncStorage.multiSet(pairs);
-    }
+    });
+
+    setToken(response.token);
+    setUser(response.record);
+    setServerAddress(nextServerAddress);
+    setCanCreate(api.getCanCreate() || false);
+    watchToken(response.token);
   };
 
   const logout = async () => {

src/services/api.ts

@@ -5,12 +5,47 @@ import {
   PermissionResponse,
 } from '../types';
 
+export type AuthCollection = 'users' | '_superusers';
+
+export type ApiError = Error & {
+  status?: number;
+  isAuthError?: boolean;
+};
+
+export type AuthUpdateListener = (auth: AuthResponse) => void | Promise<void>;
+export type AuthFailureListener = (error: unknown) => void | Promise<void>;
+
+const AUTH_ERROR_MESSAGE = /authorization token|invalid token|unauthorized|not authenticated/i;
+
+export function isAuthCollection(value: unknown): value is AuthCollection {
+  return value === 'users' || value === '_superusers';
+}
+
+export function isRevokedAuthError(error: unknown): boolean {
+  if (typeof error !== 'object' || error === null) return false;
+  const status = (error as { status?: unknown }).status;
+  return status === 401 || status === 403 || status === 404;
+}
+
+function isSessionChanged(error: unknown): boolean {
+  return (
+    typeof error === 'object' &&
+    error !== null &&
+    (error as { sessionChanged?: boolean }).sessionChanged === true
+  );
+}
+
 class UpSnapAPI {
   private token: string | null = null;
   private address: string | null = null;
   private canCreate: boolean | null = null;
+  private authCollection: AuthCollection | null = null;
+  private authEpoch = 0;
   private unauthorizedHandler: (() => Promise<void>) | null = null;
+  private authUpdateListener: AuthUpdateListener | null = null;
+  private authFailureListener: AuthFailureListener | null = null;
   private isHandlingUnauthorized = false;
+  private refreshInFlight: Promise<AuthResponse> | null = null;
 
   setToken(token: string) {
     this.token = token;
@@ -22,6 +57,7 @@ class UpSnapAPI {
 
   clearToken() {
     this.token = null;
+    this.authEpoch += 1;
   }
 
   setAddress(address: string) {
@@ -48,10 +84,30 @@ class UpSnapAPI {
     this.canCreate = null;
   }
 
+  setAuthCollection(collection: AuthCollection | null) {
+    this.authCollection = collection;
+  }
+
+  getAuthCollection(): AuthCollection | null {
+    return this.authCollection;
+  }
+
+  clearAuthCollection() {
+    this.authCollection = null;
+  }
+
   setUnauthorizedHandler(handler: (() => Promise<void>) | null) {
     this.unauthorizedHandler = handler;
   }
 
+  setAuthUpdateListener(listener: AuthUpdateListener | null) {
+    this.authUpdateListener = listener;
+  }
+
+  setAuthFailureListener(listener: AuthFailureListener | null) {
+    this.authFailureListener = listener;
+  }
+
   private async handleUnauthorized() {
     if (!this.unauthorizedHandler || this.isHandlingUnauthorized) {
       return;
@@ -66,7 +122,7 @@ class UpSnapAPI {
     }
   }
 
-  private async throwApiError(response: Response, fallbackMessage: string): Promise<never> {
+  private async errorFromResponse(response: Response, fallbackMessage: string): Promise<ApiError> {
     let message = fallbackMessage;
 
     try {
@@ -76,23 +132,26 @@ class UpSnapAPI {
       // Ignore JSON parsing errors and use the fallback message.
     }
 
-    const isAuthError =
+    const apiError = new Error(message) as ApiError;
+    apiError.status = response.status;
+    apiError.isAuthError =
       response.status === 401 ||
       response.status === 403 ||
-      /authorization token|invalid token|unauthorized|not authenticated/i.test(message);
+      AUTH_ERROR_MESSAGE.test(message);
+    return apiError;
+  }
 
-    if (isAuthError) {
+  private async throwApiError(
+    response: Response,
+    fallbackMessage: string,
+    skipUnauthorizedHandler = false,
+  ): Promise<never> {
+    const error = await this.errorFromResponse(response, fallbackMessage);
+
+    if (error.isAuthError && !skipUnauthorizedHandler) {
       await this.handleUnauthorized();
     }
 
-    const error = new Error(message) as Error & {
-      status?: number;
-      isAuthError?: boolean;
-    };
-
-    error.status = response.status;
-    error.isAuthError = isAuthError;
-
     throw error;
   }
 
@@ -108,11 +167,166 @@ class UpSnapAPI {
     return headers;
   }
 
+  private sessionChanged(): ApiError {
+    const error = new Error('Auth session changed') as ApiError & { sessionChanged: true };
+    error.sessionChanged = true;
+    error.isAuthError = true;
+    return error;
+  }
+
+  /**
+   * One refresh is shared by the expiry timer and every request that receives a 401.
+   * PocketBase returns a new auth token and record for the same collection.
+   */
+  async refreshAuth(): Promise<AuthResponse> {
+    if (!this.refreshInFlight) {
+      this.refreshInFlight = this.performRefresh().finally(() => {
+        this.refreshInFlight = null;
+      });
+    }
+
+    return this.refreshInFlight;
+  }
+
+  private async performRefresh(): Promise<AuthResponse> {
+    const epoch = this.authEpoch;
+    const tokenAtStart = this.token;
+
+    try {
+      if (!tokenAtStart || !this.address) {
+        throw Object.assign(new Error('Not authenticated'), {
+          status: 401,
+          isAuthError: true,
+        }) as ApiError;
+      }
+
+      const collections: AuthCollection[] = this.authCollection
+        ? [this.authCollection]
+        : ['users', '_superusers'];
+      let lastError: ApiError | null = null;
+
+      for (let index = 0; index < collections.length; index += 1) {
+        const collection = collections[index];
+        const response = await fetch(
+          `${this.address}/collections/${collection}/auth-refresh`,
+          {
+            method: 'POST',
+            headers: this.getHeaders(),
+          },
+        );
+
+        if (this.authEpoch !== epoch || this.token !== tokenAtStart) {
+          throw this.sessionChanged();
+        }
+
+        if (response.ok) {
+          const data = (await response.json()) as AuthResponse;
+          if (this.authEpoch !== epoch || this.token !== tokenAtStart) {
+            throw this.sessionChanged();
+          }
+          if (!data?.token) {
+            throw Object.assign(new Error('Auth refresh failed'), {
+              status: 401,
+              isAuthError: true,
+            }) as ApiError;
+          }
+
+          this.authCollection = isAuthCollection(data.record?.collectionName)
+            ? data.record.collectionName
+            : collection;
+          this.token = data.token;
+          if (this.authCollection === '_superusers') {
+            this.canCreate = true;
+          }
+
+          try {
+            await this.authUpdateListener?.(data);
+          } catch (error) {
+            console.error('Failed to persist refreshed auth', error);
+          }
+
+          return data;
+        }
+
+        lastError = await this.errorFromResponse(response, 'Auth refresh failed');
+        const tryNextCollection =
+          !this.authCollection && index < collections.length - 1 && response.status === 403;
+        if (!tryNextCollection) {
+          throw lastError;
+        }
+      }
+
+      throw (
+        lastError ??
+        (Object.assign(new Error('Auth refresh failed'), {
+          status: 401,
+          isAuthError: true,
+        }) as ApiError)
+      );
+    } catch (error) {
+      if (!isSessionChanged(error)) {
+        try {
+          await this.authFailureListener?.(error);
+        } catch (listenerError) {
+          console.error('Failed to handle auth refresh failure', listenerError);
+        }
+      }
+      throw error;
+    }
+  }
+
+  /**
+   * On 401, refresh once and retry the original request.
+   * A second 401, or a refresh the server rejects, ends the session.
+   */
+  private async request(url: string, fallbackMessage: string, init?: RequestInit): Promise<Response> {
+    const send = () =>
+      fetch(url, {
+        ...init,
+        headers: this.getHeaders(),
+      });
+
+    const response = await send();
+    if (response.ok) {
+      return response;
+    }
+
+    if (response.status === 401 && this.token) {
+      try {
+        await this.refreshAuth();
+      } catch (error) {
+        if (isSessionChanged(error)) {
+          throw error;
+        }
+        if (!isRevokedAuthError(error)) {
+          throw error;
+        }
+        await this.handleUnauthorized();
+        return this.throwApiError(response, fallbackMessage, true);
+      }
+
+      const retried = await send();
+      if (!retried.ok) {
+        if (retried.status === 401) {
+          await this.handleUnauthorized();
+          return this.throwApiError(retried, fallbackMessage, true);
+        }
+        return this.throwApiError(retried, fallbackMessage);
+      }
+      return retried;
+    }
+
+    return this.throwApiError(response, fallbackMessage);
+  }
+
   async authenticate(
     serverAddress: string,
     identity: string,
     password: string
   ): Promise<AuthResponse> {
+    this.authEpoch += 1;
+    this.token = null;
+    this.authCollection = null;
     this.address = serverAddress + '/api';
 
     const response = await fetch(
@@ -125,7 +339,7 @@ class UpSnapAPI {
     );
 
     if (!response.ok) {
-      const response = await fetch(
+      const superuserResponse = await fetch(
         `${this.address}/collections/_superusers/auth-with-password`,
         {
           method: 'POST',
@@ -134,18 +348,20 @@ class UpSnapAPI {
         }
       );
 
-      if (!response.ok) {
+      if (!superuserResponse.ok) {
-        await this.throwApiError(response, 'Authentication failed');
+        await this.throwApiError(superuserResponse, 'Authentication failed');
       }
 
-      const data: AuthResponse = await response.json();
+      const data: AuthResponse = await superuserResponse.json();
       this.token = data.token;
+      this.authCollection = '_superusers';
       this.canCreate = true;
       return data;
     }
 
     const data: AuthResponse = await response.json();
     this.token = data.token;
+    this.authCollection = 'users';
 
     const userID = data.record.id;
     const userPermissionResponse = await fetch(
@@ -165,142 +381,80 @@ class UpSnapAPI {
   }
 
   async getDevices(page = 1, perPage = 100): Promise<Device[]> {
-    const response = await fetch(
+    const response = await this.request(
       `${this.address}/collections/devices/records?page=${page}&perPage=${perPage}`,
-      {
+      'Failed to fetch devices',
-        headers: this.getHeaders(),
-      }
     );
 
-    if (!response.ok) {
-      await this.throwApiError(response, 'Failed to fetch devices');
-    }
-
     const data = await response.json();
     return data.items;
   }
 
   async getDevice(id: string): Promise<Device> {
-    const response = await fetch(
+    const response = await this.request(
       `${this.address}/collections/devices/records/${id}`,
-      {
+      'Failed to fetch device',
-        headers: this.getHeaders(),
-      }
     );
 
-    if (!response.ok) {
-      await this.throwApiError(response, 'Failed to fetch device');
-    }
-
     return response.json();
   }
 
   async createDevice(device: Partial<Device>): Promise<Device> {
-    const response = await fetch(
+    const response = await this.request(
       `${this.address}/collections/devices/records`,
+      'Failed to create device',
       {
         method: 'POST',
-        headers: this.getHeaders(),
         body: JSON.stringify(device),
-      }
+      },
     );
 
-    if (!response.ok) {
-      await this.throwApiError(response, 'Failed to create device');
-    }
-
     return response.json();
   }
 
   async updateDevice(id: string, device: Partial<Device>): Promise<Device> {
-    const response = await fetch(
+    const response = await this.request(
       `${this.address}/collections/devices/records/${id}`,
+      'Failed to update device',
       {
         method: 'PATCH',
-        headers: this.getHeaders(),
         body: JSON.stringify(device),
-      }
+      },
     );
 
-    if (!response.ok) {
-      await this.throwApiError(response, 'Failed to update device');
-    }
-
     return response.json();
   }
 
   async deleteDevice(id: string): Promise<void> {
-    const response = await fetch(
+    await this.request(
       `${this.address}/collections/devices/records/${id}`,
-      {
+      'Failed to delete device',
-        method: 'DELETE',
+      { method: 'DELETE' },
-        headers: this.getHeaders(),
-      }
     );
-
-    if (!response.ok) {
-      await this.throwApiError(response, 'Failed to delete device');
-    }
   }
 
   async wakeDevice(id: string): Promise<void> {
-    const response = await fetch(`${this.address}/upsnap/wake/${id}`, {
+    await this.request(`${this.address}/upsnap/wake/${id}`, 'Failed to wake device');
-      headers: this.getHeaders(),
-    });
-
-    if (!response.ok) {
-      await this.throwApiError(response, 'Failed to wake device');
-    }
   }
 
   async wakeGroup(id: string): Promise<void> {
-    const response = await fetch(`${this.address}/upsnap/wakegroup/${id}`, {
+    await this.request(`${this.address}/upsnap/wakegroup/${id}`, 'Failed to wake group');
-      headers: this.getHeaders(),
-    });
-
-    if (!response.ok) {
-      await this.throwApiError(response, 'Failed to wake group');
-    }
   }
 
   async sleepDevice(id: string): Promise<void> {
-    const response = await fetch(`${this.address}/upsnap/sleep/${id}`, {
+    await this.request(`${this.address}/upsnap/sleep/${id}`, 'Failed to sleep device');
-      headers: this.getHeaders(),
-    });
-
-    if (!response.ok) {
-      await this.throwApiError(response, 'Failed to sleep device');
-    }
   }
 
   async rebootDevice(id: string): Promise<void> {
-    const response = await fetch(`${this.address}/upsnap/reboot/${id}`, {
+    await this.request(`${this.address}/upsnap/reboot/${id}`, 'Failed to reboot device');
-      headers: this.getHeaders(),
-    });
-
-    if (!response.ok) {
-      await this.throwApiError(response, 'Failed to reboot device');
-    }
   }
 
   async shutdownDevice(id: string): Promise<void> {
-    const response = await fetch(`${this.address}/upsnap/shutdown/${id}`, {
+    await this.request(`${this.address}/upsnap/shutdown/${id}`, 'Failed to shutdown device');
-      headers: this.getHeaders(),
-    });
-
-    if (!response.ok) {
-      await this.throwApiError(response, 'Failed to shutdown device');
-    }
   }
 
   async scanNetwork(): Promise<NetworkScanResult[]> {
-    const response = await fetch(`${this.address}/upsnap/scan`, {
+    const response = await this.request(`${this.address}/upsnap/scan`, 'Failed to scan network');
-      headers: this.getHeaders(),
-    });
-
-    if (!response.ok) {
-      await this.throwApiError(response, 'Failed to scan network');
-    }
 
     const data = await response.json();
     if (data.devices && Array.isArray(data.devices)) {

src/services/jwtExpiry.ts

@@ -0,0 +1,41 @@
+const BASE64_ALPHABET = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
+
+function decodeBase64Url(segment: string): string {
+  const normalized = segment.replace(/-/g, '+').replace(/_/g, '/');
+  const padded = normalized + '='.repeat((4 - (normalized.length % 4)) % 4);
+  const bytes: number[] = [];
+
+  for (let index = 0; index < padded.length; index += 4) {
+    const a = BASE64_ALPHABET.indexOf(padded[index]);
+    const b = BASE64_ALPHABET.indexOf(padded[index + 1]);
+    const c = padded[index + 2] === '=' ? 0 : BASE64_ALPHABET.indexOf(padded[index + 2]);
+    const d = padded[index + 3] === '=' ? 0 : BASE64_ALPHABET.indexOf(padded[index + 3]);
+    if (a < 0 || b < 0 || c < 0 || d < 0) {
+      throw new Error('Invalid base64url');
+    }
+
+    const chunk = (a << 18) | (b << 12) | (c << 6) | d;
+    bytes.push((chunk >> 16) & 255);
+    if (padded[index + 2] !== '=') bytes.push((chunk >> 8) & 255);
+    if (padded[index + 3] !== '=') bytes.push(chunk & 255);
+  }
+
+  return String.fromCharCode(...bytes);
+}
+
+/**
+ * Reads the JWT `exp` claim in milliseconds.
+ * Scheduling only; the signature is not verified.
+ */
+export function getJwtExpiryMs(token: string): number | null {
+  const segment = token.split('.')[1];
+  if (!segment) return null;
+
+  try {
+    const payload = JSON.parse(decodeBase64Url(segment)) as { exp?: unknown };
+    if (typeof payload.exp !== 'number' || !Number.isFinite(payload.exp)) return null;
+    return payload.exp * 1000;
+  } catch {
+    return null;
+  }
+}